Impact of Pesticide Use on Gut Microbiota and Health: A Systematic Review of Findings in Both Humans and Animal Models

<b>Background/objective:</b> The widespread use of pesticides in modern agriculture has raised increasing concern about their potential adverse effects on human health. Exposure to these compounds has been linked to multiple negative health outcomes. This systematic review aims to evaluate and synthesise the available scientific evidence on the effects of pesticide exposure on human health during agricultural production-with particular emphasis on alterations in gut microbiota and intestinal membrane permeability-by integrating results from experimental and observational studies conducted on animals and humans. <b>Methods:</b> This systematic review was conducted in accordance with PRISMA guidelines. A systematic literature search was carried out using the main databases Medline/PubMed, Embase and Web of Science, introducing the search algorithm "pesticides" AND "gut microbiota", from which a total of seven systematic reviews that met our inclusion criteria were found and subsequently analysed. The quality assessment was based on the principles of evidence-based medicine. This systematic review was registered in the OSF. <b>Results:</b> The findings indicate that prenatal exposure to pesticides is linked to adverse outcomes in foetal development. Additionally, pesticide exposure affects metabolic, immune, and nervous system function due to alterations in gut microbiota composition and membrane permeability. Evidence from animal model studies complements human data by providing insight into the underlying biological mechanisms, such as oxidative stress, liver dysfunction, alterations in hormonal signalling and activation of the inflammatory response. <b>Conclusions:</b> Public health strategies should prioritise reducing pesticide exposure, strengthening environmental protection and supporting further research on gut microbiota modulation and intestinal membrane permeability. Such measures may contribute to the prevention and mitigation of pesticide-related health disorders. <b>Limitations:</b> Human data are insufficient to establish clear causal relationships. Moreover, substantial variability among pesticide types and the difficulty of distinguishing the effects of complex mixtures from those of individual compounds complicate interpretation of the findings.